1. Field of the Invention
The present invention relates to a filter press, for cake or precoat filtration, including one or more filter units, each of which comprises slurry frames, filter plates, and support sheets or surfaces; each filter plate is provided with at least one filtrate discharge, and each support sheet or surface, which is disposed on one side of a given filter plate, has associated therewith one of the slurry frames, which has a filling space which is directed toward the caking side of the support sheet or surface, an upper and lower connection for venting and discharge, and a supply conduit for medium which is to be filtered.
2. Description of the Prior Art
Precautions have already been taken with a filter press of the aforementioned general type in order to optimally design for the formation of turbulence and for the distribution of the filtering aid in the filling space of a given slurry frame of the filter press (see Deutscher Braumeister und Malzmeister, volume Nr. 6, 1983, page 237, right column, and page 238, left column). These precautions consist in replacing the up-to-now large slots for the entry of the medium which is to be filtered into the filling space by a supply conduit having an outlet which comprises small holes; furthermore, special baffle plates are built into the filling space. Although these precautions lead to improved distribution of the filtering aid which is to be caked-on onto the support sheets or surfaces associated with the respective filling space, it is not possible to increase the filtration output of the filter press per m.sup.2 of the filter surface area by any multiple as a result of the filtering aid caking which is improved by the aforementioned precautions. Furthermore, the limited ability of the filling space of a respective slurry frame to receive material also limits such an increase in output. At increased filtration output, the slurry frame is rapidly depleted, and must thereafter be cleaned each time, for which purpose the filter press must be manually opened, and the residue which fills the respective filling space and is retained by the support sheets or surfaces also must be removed. The maintenance operation increases the filtration time, and is therefore not economically feasible for a filter press which is required to have a high filtration output.
An object of the present invention is to provide a filter press for cake or precoat filtration, which while providing uniform caking of the filtering aid, not only makes it possible, while the filter unit is closed, to remove from the filling spaces the residues, which have caked onto the support sheets or surfaces, and comprise filtering aid and impurities, but also permits a considerably greater filtration output than is possible with previous filter presses of this general type.